Light emitting device and lighting system

ABSTRACT

A light emitting device includes a conductive support member, a first conductive layer disposed on the conductive support member, a second conductive layer disposed on the first conductive layer, a light emitting structure including a first semiconductor layer, layer disposed on the second conductive layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, and an insulation layer disposed between the first conductive layer and the second conductive layer. The first conductive layer includes a first expansion part penetrating through the second conductive layer, the second semiconductor layer and the active layer, and includes a second expansion part extending from the first expansion part and being disposed in the first semiconductor layer. The insulation layer is disposed on the lateral surface of the first expansion part, and the lateral surface of the second expansion part contacts with the first semiconductor layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser.No. 13/179,192 filed Jul. 8, 2011, which claims priority from KoreanApplication No. 10-2010-0067115, filed Jul. 12, 2010, the subjectmatters of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a light emitting device and a lightingsystem.

BACKGROUND

A light emitting diode (LED) is a semiconductor element for convertingelectric energy into light. As compared with existing light sources suchas a fluorescent lamp and an incandescent electric lamp and so on, theLED has advantages of low power consumption, a semi-permanent span oflife, a rapid response speed, safety and an environment-friendliness.For this reason, many researches are devoted to substitution of theexisting light sources with the LED. The LED is now increasingly used asa light source for lighting devices, for example, various lamps usedinteriorly and exteriorly, a liquid crystal display device, an electricsign and a street lamp and the like.

SUMMARY

One embodiment is a light emitting device. The light emitting devicecomprises: a conductive support member; a first conductive layerdisposed on the conductive support member; a second conductive layerdisposed on the first conductive layer; a light emitting structurecomprising a first semiconductor layer disposed on the second conductivelayer, a second semiconductor layer disposed between the firstsemiconductor layer and the second conductive layer, and an active layerdisposed between the first semiconductor layer and the secondsemiconductor layer; and an insulation layer disposed between the firstconductive layer and the second conductive layer, wherein the firstconductive layer includes a conductive via penetrating through thesecond conductive layer, the second semiconductor layer and the activelayer and being disposed in the first semiconductor layer, wherein theinsulation layer is disposed on a lateral surface of the conductive via,wherein a height of the conductive via is greater than a height of theinsulation layer disposed on the lateral surface of the conductive via,and wherein the lateral surface of the conductive via is inclined.

Another embodiment is a light emitting device. The light emitting devicecomprises: a conductive support member; a first conductive layerdisposed on the conductive support member; a second conductive layerdisposed on the first conductive layer; a light emitting structurecomprising a first semiconductor layer disposed on the second conductivelayer, a second semiconductor layer disposed between the firstsemiconductor layer and the second conductive layer, and an active layerdisposed between the first semiconductor layer and the secondsemiconductor layer; and an insulation layer disposed between the firstconductive layer and the second conductive layer, wherein the firstconductive layer includes a conductive via penetrating through thesecond conductive layer, the second semiconductor layer and the activelayer and being disposed in the first semiconductor layer, wherein theinsulation layer is disposed on a lateral surface of the conductive via,wherein a height of the conductive via is greater than a height of theinsulation layer disposed on the lateral surface of the conductive via,and wherein a width of a lower portion of the conductive via is greaterthan a width of a upper portion of the conductive via.

Further another embodiment a light emitting device. The light emittingdevice comprises: a conductive support member; a first conductive layerdisposed on the conductive support member; a second conductive layerdisposed on the first conductive layer; a light emitting structurecomprising a first semiconductor layer disposed on the second conductivelayer, a second semiconductor layer disposed between the firstsemiconductor layer and the second conductive layer, and an active layerdisposed between the first semiconductor layer and the secondsemiconductor layer; and an insulation layer disposed between the firstconductive layer and the second conductive layer, wherein the firstconductive layer includes a conductive via penetrating through thesecond conductive layer, the second semiconductor layer and the activelayer and being disposed in the first semiconductor layer, wherein theinsulation layer is disposed on a lateral surface of the conductive via,wherein a height of the conductive via is greater than a height of theinsulation layer disposed on the lateral surface of the conductive via,and wherein an area of a top surface of the second semiconductor layeris greater than an area of a bottom surface of the second semiconductorlayer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a cross section of a light emitting deviceaccording to an embodiment of the present disclosure.

FIG. 2A is a view showing a top surface of the light emitting deviceaccording to the embodiment of the present disclosure.

FIG. 2B is a view showing a cross section of the light emitting devicetaken along line A-A′ of FIG. 2A.

FIG. 2C is a view showing in detail the area ‘B’ of FIG. 2B.

FIG. 2D is a view showing a cross section of another embodiment of thelight emitting device shown in FIG. 2B.

FIGS. 3A to 3K are views showing a method of manufacturing the lightemitting device according to the embodiment of the present disclosure.

FIG. 4 is a view showing schematically a light emitting device package.

FIG. 5 is a view showing a backlight unit including the light emittingdevice package according to the embodiment of the present disclosure.

FIG. 6 is a perspective view showing a lighting system 1500 includingthe light emitting device package shown in FIG. 4.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the drawings, a thickness or size of each layer may be magnified,omitted or schematically shown, simply for purpose of convenience andclarity of description. The size of each component may not necessarilyrepresent its actual size.

Further, when an element is referred to as being ‘on’ or “under” anotherelement, it may be directly on/under the element, or one or moreintervening elements may also be present. When an element is referred toas being ‘on’ or ‘under’, ‘under the element’ as well as ‘on theelement’ may be included based on the element

Hereinafter, an embodiment of the present disclosure will be describedin detail with reference to the accompanying drawings.

[Light Emitting Device]

FIG. 1 is a view showing a cross section of a vertical light emittingdevice 200 including a via hole electrode in accordance with anembodiment.

Hereafter, for the sake of convenience of description, it is assumedthat a semiconductor layer 270 electrically connected to an n-typeconductive layer 220 through conductive vias 220 a, 220 b and 220 c isan n-type semiconductor layer, and a semiconductor layer 250 formedbetween a p-type conductive layer 240 and an active layer 260 is ap-type semiconductor layer.

In the light emitting device shown in FIG. 1, the conductive vias 220 a,220 b and 220 c are formed to penetrate through the p-type conductivelayer 240, the p-type semiconductor layer 250 and the active layer 260from the n-type conductive layer 220, and extend to a certain area ofthe n-type semiconductor layer 270. The structure of the light emittingdevice 200 shown in FIG. 1 provides excellent light-extractionefficiency because the top surface of the n-type semiconductor layer 270actually emitting light is not blocked by an electrode.

FIG. 2A is a view showing a top surface of a light emitting device 300according to another embodiment. FIG. 2B is a view showing a crosssection of the light emitting device 300 taken along line A-A′ of FIG.2A. FIG. 2C is an enlarged view showing the area ‘B’ of FIG. 2B.

Referring to FIGS. 2A to 2C, a light emitting device 300 according toanother embodiment includes a conductive support member 310, a firstconductive layer 320, a second conductive layer 330, a light emittingstructure 340, 350 and 360, and an insulation layer 370. Here, for thesake of convenience of description, it is assumed that the firstconductive layer 320 is an n-type conductive layer, the secondconductive layer 330 is a p-type conductive layer, the firstsemiconductor layer 340 is an n-type semiconductor layer, and the secondsemiconductor layer 350 is a p-type semiconductor layer.

The conductive support member 310 is formed including at least one ofAu, Ni, Al, Cu, W, Si, Se, Mo and GaAs. For example, the conductivesupport member 310 is made of a metal alloy of Si and Al.

The first conductive layer 320 includes at least one conductive via Band a conductive part 320 a contacting with the conductive supportmember 310.

The area ratio of the bottom surface of the conductive via B shown inFIG. 2B to the top surface of the conductive via B is from 1 to 2.5.Here, the bottom surface of the conductive via B corresponds to asurface which comes in direct contact with the conductive part 320 a.The top surface of the conductive via B corresponds to a surface whichcomes in direct contact with the first semiconductor layer 340.

The thickness of the conductive part 320 a shown in FIG. 2C is equal toor larger than 0.7 and equal to or less than 2 μm, and more preferablyis approximately 1 μm.

The conductive via B includes a first expansion part 320 b and a secondexpansion part 320 c, all of which are shown in FIG. 2C. Both the firstexpansion part 320 b and the second conductive layer 330, the secondsemiconductor layer 350 and an active layer 360 are located in the samelayer. The second expansion part 320 c extends from the first expansionpart 320 b and is disposed at a certain area of the first semiconductorlayer 340. The conductive part 320 a, the first expansion part 320 b andthe second expansion part 320 c allows the conductive support member 310to be electrically connected to the first semiconductor layer 340.

The first conductive layer 320 is electrically directly connected to thefirst semiconductor layer 340 through the top surface and the lateralsurface of the second expansion part 320 c.

Since the conductive support member 310 is electrically connected to thefirst semiconductor layer 340 by the first conductive layer 320, thefirst conductive layer 320 is made of a material having a minimumcontact resistance with the conductive support member 310 and the firstsemiconductor layer 340.

The first conductive layer 320 is formed including at least one of Ag,Al, Au, Pt, Ti, Cr, and W.

The insulation layer 370 electrically insulates the first conductivelayer 320 from layers other than the conductive support member 310 andthe first semiconductor layer 340.

Specifically, the insulation layer 370 includes a first insulation layer370 a and a second insulation layer 370 b. The first insulation layer370 a is disposed on the lateral surface of the first expansion part 320b, and electrically insulates the second conductive layer 330 from thefirst expansion part 320 b, the second semiconductor layer 350 from thefirst expansion part 320 b, and the active layer 360 from the firstexpansion part 320 b.

The second insulation layer 370 b is disposed between the firstconductive layer 320 and the second conductive layer 330, so that thefirst conductive layer 320 is electrically insulated from the secondconductive layer 330.

The height of the first insulation layer 370 a is less than that of theconductive via B. The height of the conductive via B is greater thanthat of the first insulation layer 370 a to the contrary. Here, theheight of the first insulation layer 370 a corresponds to a height inthe direction of the first semiconductor layer 340 on the basis of thetop surface of the conductive part 320 a. The height of the conductivevia B corresponds to a height in the direction of the firstsemiconductor layer 340 on the basis of the top surface of theconductive part 320 a. Here, it should be noted that the referencesurface for the height includes not only the top surface of theconductive part 320 a but also the bottom surface of the conductive part320 a and the top or bottom surface of the conductive support member310.

The height of the first insulation layer 370 a may be equal to that ofthe first expansion part 320 b. Here, the height of the first expansionpart 320 b corresponds to a height in the direction of the firstsemiconductor layer 340 on the basis of the top surface of theconductive part 320 a. Here, it should be noted that the referencesurface for the height includes not only the top surface of theconductive part 320 a but also the bottom surface of the conductive part320 a and the top or bottom surface of the conductive support member310.

Meanwhile, though not shown, the height of the first insulation layer370 a may be greater than that of the first expansion part 320 b. Thatis, the first insulation layer 370 a may be disposed on a portion of thelateral surface of the second expansion part 320 c.

The thickness of the first insulation layer 370 a is equal to or largerthan 200 nm and equal to or less than 1000 nm. When the first insulationlayer 370 a has a thickness within the range, the stability of the firstinsulation layer 370 a is improved. More preferably, it is better tohave a thickness of about 500 nm.

The area of the bottom surface of the second expansion part 320 c isgreater than that of the top surface of the first expansion part 320 b.Here, the top surface of the first expansion part 320 b contacts withthe bottom surface of the second expansion part 320 c. Here, the arearatio of the bottom surface of the second expansion part 320 c to thetop surface of the first expansion part 320 b is from 1 to 1.4.

The width of the second expansion part 320 c may be equal to or greaterthan that of the first expansion part 320 b. Also, the width of thesecond expansion part 320 c may be equal to or less than the sum of thewidth of the first expansion part 320 b and the widths of two firstinsulation layers 370 a. The width of the second expansion part 320 cmay be greater than the sum of the width of the first expansion part 320b and the thicknesses of two first insulation layers 370 a.

The insulation layer 170 includes at least any one of silicon oxide(SiO₂), silicon nitride (SiO_(x)N_(y), Si_(x)N_(y)), metal oxide (Al₂O₃)and fluoride based compound.

In the embodiment shown in FIGS. 2A to 2C, it is possible to increasethe contact area between the first conductive layer 320 and the firstsemiconductor layer 340 by minimizing the insulation area between thesecond expansion part 320 c and the first semiconductor layer 340.

The second conductive layer 330 is formed on the insulation layer 370.There is no second conductive layer 330 in the area through which thefirst expansion part 320 b penetrates.

The second conductive layer 330 is formed including at least one of Ag,Al, Pt, Ni, Pt, Pd, Au, Ir and a transparent conductive oxide (ITO andGZO). This intends to minimize the contact resistance of the secondsemiconductor layer 350 because the second conductive layer 330 contactselectrically with the second semiconductor layer 350.

The second conductive layer 330 may include a reflective layer or anohmic layer for reflecting light emitted from the active layer 360 inthe direction of the active layer 360.

The second conductive layer 330 includes at least one area exposedoutward. On the exposed area, p-type electrode pads 131 a and 131 b towhich external electric power is applied are disposed. On the exposedarea, the second semiconductor layer 350, the active layer 360 and thefirst semiconductor layer 340 are not disposed. The exposed area is, asshown in FIG. 2A, disposed at the corner of the light emitting device300, and the p-type electrode pads 131 a and 131 b are disposed on theexposed area. When the p-type electrode pads 131 a and 131 b aredisposed at the corner of the light emitting device 300, the lightemitting area of the light emitting device 300 can be maximized.

The thickness of the second conductive layer 330 is equal to or larger50 nm and equal to or less than 1000 nm.

The light emitting structure 340, 350 and 360 is disposed on the secondconductive layer 330.

The light emitting structure 340, 350 and 360 includes the firstsemiconductor layer 340, the second semiconductor layer 350 and theactive layer 360. Specifically, the second semiconductor layer 350 isdisposed on the second conductive layer 330. The first semiconductorlayer 340 is disposed on the second semiconductor layer 350. The activelayer 360 is disposed between the first semiconductor layer 340 and thesecond semiconductor layer 350.

The first semiconductor layer 340 is formed of a semiconductor materialhaving an empirical formula of In_(x)Al_(y)Ga_(1−x−y)N (0≦x≦1, 0≦y≦1,0≦x+y≦1), for example, InAlGaN, GaN, AlGaN, InGaN, AlInN, AIN and InNand the like. An n-type dopant such as Si, Ge and Sn and the like may bedoped on the first semiconductor layer 340.

The second semiconductor layer 350 is formed of a semiconductor materialhaving an empirical formula of In_(x)Al_(y)Ga_(1−x−y)N (0≦x≦1, 0≦y≦1,0≦x+y≦1), for example, InAlGaN, GaN, AlGaN, InGaN, AlInN, AIN and InNand the like. A p-type dopant such as Mg and Zn and the like may bedoped on the second semiconductor layer 350.

The active layer 360 is formed of a semiconductor material having anempirical formula of In_(x)Al_(y)Ga_(1−x−y)N (0≦x≦1, 0≦y≦1, 0≦x+y≦1).When the active layer 360 is formed in the multiple quantum well (MQW)structure, the active layer 360 is formed by stacking a plurality ofwell layers and a plurality of barrier layers, for example, at a cycleof InGaN well layer/GaN barrier layer.

The active layer 360 is formed of another material in accordance withthe material constituting the first semiconductor layer 340 and thesecond semiconductor layer 350. In other words, the active layer 360converts energy by the recombination of electrons and holes into lightand emits. Therefore, it is recommended that the active layer 360 beformed of a material having an energy band gap smaller than those of thefirst semiconductor layer 340 and the second semiconductor layer 350.

Meanwhile, the active layer 360 exposed outward is able to function as acurrent leakage path during the working of the light emitting device300. Here, such a problem is prevented by forming a passivation layer380 on the side of the light emitting device 300. The passivation layer380 protects the light emitting structure, especially the active layer360 from the outside and prevents a leakage current from flowing. Thepassivation layer 380 is formed of silicon oxide (SiO₂), silicon nitride(SiO_(x)N_(y), Si_(x)N_(y)) and fluoride based compound. Otherwise, thepassivation layer 380 may be a composite layer constituted by theaforementioned materials.

Regarding the light emitting device 300 according to the embodimentshown in FIGS. 2A to 2C, when the first insulation layer 370 a formed onthe side of the conductive via B is minimized, the contact area betweenthe first conductive layer 320 and the first semiconductor layer 340 canbe more increased than that of the light emitting device shown inFIG. 1. When the contact area is increased, the electric current flowwithin the light emitting device 300 is activated, so that light outputand light-extraction efficiency are increased. Therefore, there is anadvantage of improving electrical characteristics.

In the light emitting device shown in FIG. 1, the greater the height ofthe conductive via 220 a is, the more the side of the conductive via 220a is inclined. Therefore, the area of the top surface of the conductivevia 220 a electrically connected to the n-type semiconductor layer 270is reduced. However, though the light emitting device according to theembodiment shown in FIGS. 2A to 2C includes a conductive via B the sameas the conductive via 220 a shown in FIG. 1, the light emitting devicehas an advantage of obtaining a contact area larger than that of thelight emitting device shown in FIG. 1.

FIG. 2D is a view showing a cross section of a light emitting device300′ according to another embodiment of the light emitting device 300shown in FIG. 2B. The description of the same components as those ofFIG. 2B will be omitted.

A conductive via B′ of the light emitting device 300′ according toanother embodiment shown in FIG. 2D has a roughness surface.Specifically, The top surface of the conductive via B′ contacting withthe first semiconductor layer 340′ has the roughness surface. When thetop surface of the conductive via B′ has the roughness surface, thecontact resistance is reduced due to the surface area increase.Therefore, ohmic contact characteristics of the light emitting device300′ can be improved. Besides, the roughness of the surface changes thecritical angle of light and allows the light to be easily extracted, sothat the light-extraction efficiency of the light emitting device 300′can be improved. Here, the roughness surface has a cycle in a microunit. However the cycle is not limited to this. The roughness can beununiformly formed.

The first semiconductor layer 340′ of the light emitting device 300′according to another embodiment has a roughness surface. Specifically,in the first semiconductor layer 340′, the exposed top surface of andthe ohmic contact surface contacting with the top surface of theconductive via B′ have the roughness surface. When the top surface andthe ohmic contact surface have the roughness surface, the contactresistance is reduced due to the surface area increase. Therefore, theohmic contact characteristics of the light emitting device 300′ can beimproved. Besides, the roughness of the surface changes the criticalangle of light and allows the light to be easily extracted, so that thelight-extraction efficiency of the light emitting device 300′ can beimproved. Here, the roughness surface has a cycle in a micro unit.However the cycle is not limited to this. The roughness can beununiformly formed.

[Method for Manufacturing the Light Emitting Device]

FIGS. 3A to 3K are views showing a method of manufacturing the lightemitting device according to the embodiment.

As shown in FIG. 3A, a first semiconductor layer 440, an active layer460 and a second semiconductor layer 450, all of which are included in alight emitting structure, are sequentially formed.

First, the first semiconductor layer 440, the active layer 460 and thesecond semiconductor layer 450 are sequentially grown on a semiconductorgrowth substrate (not shown) by using a semiconductor growth processsuch as a metal organic chemical vapor deposition (MOCVD) or a molecularbeam epitaxy (MBE) and a hydride vapour phase epitaxy (HVPE), etc.

The first semiconductor layer 440 is formed by doping an n-type dopantsuch as Si, Ge and Sn and the like into a semiconductor material havingan empirical formula of In_(x)Al_(y)Ga_(1−x−y)N (0≦x≦1, 0≦y≦1, 0≦x+y≦1),for example, InAlGaN, GaN, AlGaN, InGaN, AlInN, AIN and InN and thelike.

The active layer 460 is formed of a semiconductor material having anempirical formula of In_(x)Al_(y)Ga_(1−x−y)N (0≦x≦1, 0≦y≦1, 0≦x+y≦1).When the active layer 460 is formed in the multiple quantum well (MQW)structure, the active layer 460 is formed by stacking a plurality ofwell layers and a plurality of barrier layers, for example, at a cycleof InGaN well layer/GaN barrier layer.

The active layer 460 is formed of another material in accordance withthe material constituting the first semiconductor layer 440 and thesecond semiconductor layer 450. In other words, the active layer 460converts energy by the recombination of electrons and holes into lightand emits. Therefore, it is recommended that the active layer 460 beformed of a material having an energy band gap smaller than those of thefirst semiconductor layer 440 and the second semiconductor layer 450.

The second semiconductor layer 450 is formed by doping a p-type dopantsuch as Mg, Zn and the like into a semiconductor material having anempirical formula of In_(x)Al_(y)Ga_(1−x−y)N (0≦x≦1, 0≦y≦1, 0≦x+y≦1),for example, InAlGaN, GaN, AlGaN, InGaN, AlInN, AIN and InN and thelike.

As shown in FIG. 3B, the second semiconductor layer 450, the activelayer 460 and the first semiconductor layer 440 are etched (firstetching) by using a common exposure process and an etching process, sothat at least one first etching hole 420 a is formed. Specifically, thesecond semiconductor layer 450 and the active layer 460 are etched andpenetrated, and the first semiconductor layer 440 is etched to apredetermined depth, and then the first etching hole 420 a is formed.The first etching hole 420 a is formed by using an etching process, forexample, ICP-RIE and the like.

As shown in FIG. 3C, an insulation material is deposited within thefirst etching hole 420 a, and then a first insulation layer 470 a isformed on the side wall of the first etching hole 420 a. The insulationmaterial of the first insulation layer 470 a includes at least one ofsilicon oxide (SiO₂), silicon nitride (SiO_(x)N_(y), Si_(x)N_(y)), metaloxide (Al₂O₃) and fluoride based compound.

As shown in FIG. 3D, the first semiconductor layer 440 is etched (secondetching), so that a second etching hole 420 b is formed to have a depthgreater than that of the first etching hole 420 a. Here, the secondetching hole 420 b is formed by etching the basal surface of the firstetching hole 420 a, i.e., a portion of the first semiconductor layer440. The second etching hole 420 b is formed by using an etchingprocess, for example, ICP-RIE and the like.

As shown in FIG. 3E, a first conductive via 421 a is formed bydepositing a conductive material in the second etching hole 420 b. Here,the first conductive via 421 a corresponds to a portion of a second viahole to be formed through a subsequent process. The conductive materialconstituting the first via hole 421 a includes at least one of Ag, Al,Au, Pt, Ti, Cr and W.

As shown in FIG. 3F, a second conductive layer 430 is formed bydepositing a conductive material on the second semiconductor layer 450.Here, the conductive material constituting the second conductive layer430 includes at least one of Ag, Al, Pt, Ni, Pt, Pd, Au, Ir and atransparent conductive oxide. The transparent conductive oxide includesone of ITO and GZO. Here, the second conductive layer 430 is constitutedby the transparent conductive oxide because the electrical contactbetween the second conductive layer 430 and the second semiconductorlayer 450 not only minimizes the contact resistance between the secondsemiconductor layer 450 and the second conductive layer 430, but alsoimproves light emission efficiency by reflecting outwardly lightgenerated from the active layer 460.

As shown in FIG. 3G, a second insulation layer 470 b is formed bydepositing an insulation material on the second conductive layer 430.The insulation material of the second insulation layer 470 b includes atleast one of silicon oxide (SiO₂), silicon nitride (SiO_(x)N_(y),Si_(x)N_(y)), metal oxide (Al₂O₃) and fluoride based compound.

As shown in FIG. 3H, a second conductive via 421 b is formed bydepositing a conductive material, and then a first conductive layer 420is formed. The second conductive via 421 b corresponds to a structurepenetrating through the second conductive layer 430, the secondsemiconductor layer 450 and the active layer 460, and projects to acertain area of the first semiconductor layer 440.

As shown in FIG. 3I, a conductive support member 410 is formed under thefirst conductive layer 420. The constituent material of the conductivesupport member 410 includes at least one of Au, Ni, Al, Cu, W, Si, Seand GaAs. For example, the conductive support member 310 is made of ametal alloy of Si and Al. The conductive support member 410 is formed byusing a plating method or bonding method in accordance with a materialselected from a group consisting of the aforementioned materials.

As shown in FIG. 3J, the corner of the light emitting structure isetched. More specifically, the first semiconductor layer 440, the activelayer 460 and the second semiconductor layer 450 which are located atthe corner of the light emitting structure are etched, and then aportion of the second conductive layer 430 is exposed outward. As aresult, an exposed area is formed. The light emitting structure isetched by using ICP-RIE method and the like.

As shown in FIG. 3K, an electrode pad is formed by depositing aconductive material on the exposed area of the second conductive layer430 or by plating or bonding an electrode material on the exposed area.

[Light Emitting Device Package]

Hereafter, a light emitting device package according to the embodimentwill be described with reference to FIG. 4. FIG. 4 shows schematically alight emitting device package 1000.

As shown in FIG. 4, the light emitting device package 1000 according tothe embodiment includes a package body 1100, a first electrode layer1110, a second electrode 1120, a light emitting device 1200 and a filler1300.

The package body 1100 is formed including a silicon material, asynthetic resin material or a metallic material. Inclined surfaces areformed around the light emitting device 1200, thereby improving thelight-extraction efficiency.

The first electrode layer 1110 and the second electrode 1120 aredisposed in the package body 1100. The first electrode layer 1110 andthe second electrode 1120 are electrically isolated from each other andsupply electric power to the light emitting device 1200. The firstelectrode layer 1110 and the second electrode 1120 reflect lightgenerated from the light emitting device 1200 and increase luminousefficiency. The first electrode layer 1110 and the second electrode 1120also exhaust heat generated from the light emitting device 1200.

The light emitting device 1200 is electrically connected to the firstelectrode layer 1110 and the second electrode 1120. The light emittingdevice 1200 is disposed on the package body 1100 or is disposed oneither the first electrode layer 1110 or the second electrode 1120.

The light emitting device 1200 is also electrically connected to thefirst electrode layer 1110 and the second electrode 1120 in a wirebonding manner or in a flip-chip manner and in a die-bonding process.

The filler 1300 is formed to surround and protect the light emittingdevice 1200. The filler 1300 includes a fluorescent material and changesthe wavelength of light emitted from the light emitting device 1200.

The light emitting device package 1000 is equipped with one or aplurality of at least one out of the light emitting devices disclosed inthe embodiments. There is no limited to the number of the light emittingdevices.

A plurality of the light emitting device packages 1000 according to theembodiment are arrayed on the support member. An optical member such asa light guide plate, a prism sheet and a diffusion sheet and the likemay be disposed on the optical path of the light emitting device package1000. Such a light emitting device package 1000, the support member andthe optical member are able to function as a light unit.

Another embodiment can be implemented by a display device, a pointingdevice and a lighting device and the like, all of which include thesemiconductor light emitting device or the light emitting device packagewhich has been described in the aforementioned embodiments. For example,the lighting device may include a lamp and a street lamp.

[Backlight Unit (BLU)]

FIG. 5 is a view showing a backlight unit 1100 including light emittingdevice packages according to an embodiment. The backlight unit 1100shown in FIG. 5 is an example of lighting systems, and is not limitedthereto.

Referring to FIG. 5, the backlight unit 1100 includes a bottom frame1140, a light guide member 1120 disposed within the bottom frame 1140,and a light emitting module 1110 disposed on at least one lateralsurface or the bottom surface of the light guide member 1120. Inaddition, a reflection sheet 1130 may be disposed under the light guidemember 1120.

The bottom frame 1140 has a box shape with an opened topside toaccommodate the light guide member 1120, the light emitting module 1110and the reflection sheet 1130. The bottom frame 1140 is formed of ametallic material or a resin material, but is not limited thereto.

The light emitting module 1110 includes a substrate 300 and a pluralityof light emitting device packages 200 of the embodiment. The lightemitting device packages is disposed on the substrate. The plurality oflight emitting device packages 200 provides light to the light guidemember 1120.

As shown in FIG. 5, the light emitting module 1110 is disposed on atleast one of inner surfaces of the bottom from 1140. Thus, the lightemitting module 1110 provides light toward at least one lateral surfaceof the light guide member 1120.

Alternatively, the light emitting module 1110 is disposed on the bottomsurface of the bottom frame 1140 to provide light toward the bottomsurface of the light guide member 1120. This may be variously variedaccording to the design of the backlight unit. That is, the spirit andscope of the present disclosure is not limited thereto.

The light guide member 1120 is disposed within the bottom frame 1140.The light guide member 1120 receives light from the light emittingmodule 1110 and guide the light to a display panel (not shown) assurface light.

For example, the light guide member 1120 is a light guide panel (LGP).The LGP is formed of an acryl-based resin such as polymethylmethacrylate(PMMA) or one of polyethylene terephthlate (PET), poly carbonate (PC),cyclic olefin copolymer (COC), and polyethylene naphthalate (PEN).

An optical sheet 1150 is disposed above the light guide member 1120. Forexample, the optical sheet 1150 includes at least one of a diffusionsheet, a condensing sheet, a brightness enhancement sheet, and afluorescence sheet. For example, the optical sheet 1150 is formed bysequentially stacking such a diffusion sheet, a condensing sheet, abrightness enhancement sheet, and a fluorescence sheet. In this case,the diffusion sheet 1150 uniformly diffuses light emitted from the lightemitting module 1110, and the diffused light is condensed on the displaypanel (not shown) by the condensing sheet. Here, light output throughthe condensing sheet is randomly polarized light. The brightnessenhancement sheet enhances polarization of the light output through thecondensing sheet. For example, the condensing sheet may be a horizontaland/or vertical prism sheet. Also, the brightness enhancement sheet maybe a dual brightness enhancement film. The fluorescence sheet may be atransparent plate or film including a phosphor.

The reflection sheet 1130 is disposed under the light guide member 1120.The reflection sheet 1130 reflects light emitted through the bottomsurface of the light guide member 1120 toward a light exit surface ofthe light guide member 1120.

The reflection sheet 1130 is formed of a resin material having a highreflectivity such as PET, PC, and PVC resins, but is not limitedthereto.

[Lighting System]

FIG. 6 is a perspective view showing a lighting system 1500 includingthe light emitting device package shown in FIG. 4.

Referring to FIG. 6, the lighting system 1500 includes a case 1510, alight emitting module 1530 disposed on the case 1510, a cover 1550connected to the case 1510, and a connection terminal 1570 connected tothe case 1510 and supplied with an electric power from an external powersupply.

The case 1510 is formed of a material having an excellent heat radiatingcharacteristic, for example, a metal material or a resin material.

The light emitting module 1530 includes a board 1531 and at least onelight emitting device package 1533 which is based on the embodiment andis mounted on the board 1531. The plurality of the light emitting devicepackages 1533 are radially arranged apart from each other at apredetermined interval on the board 1531.

The board 1531 is an insulating substrate on which a circuit pattern hasbeen printed, and includes, for example, a printed circuit board (PCB),a metal core PCB, a flexible PCB, a ceramic PCB, an FR-4 substrate, etc.

Also, the board 1531 is formed of a material capable of efficientlyreflecting light. The surface of the board 1531 may have a color capableof efficiently reflecting light, such as white or silver.

The at least one light emitting device package 1533 is disposed on theboard 1531. Each of the light emitting device packages 1533 includes atleast one light emitting diode (LED) chip. The LED chip includes both aLED emitting red, green, blue or white light and a UV LED emittingultraviolet (UV).

The light emitting module 1530 can have various combinations of thelight emitting device packages so as to obtain desired color andluminance. For example, the light emitting module 1530 can have acombination of a white LED, a red LED and a green LED in order to obtaina high color rendering index (CR1).

The connection terminal 1570 is electrically connected to the lightemitting module 1530 in order to supply power. The connection terminal1570 is screwed and connected to an external power in the form of asocket. However, there is no limit to the method for connecting theconnection terminal 1570 to an external power. For example, theconnection terminal 1570 may be made in the form of a pin and insertedinto the external power, or may be connected to the external powerthrough a power line.

The features, structures and effects and the like described in theembodiments are included in at least one embodiment of the presentdisclosure and are not necessarily limited to one embodiment.Furthermore, the features, structures and effects and the like providedin each embodiment can be combined or modified in other embodiments bythose skilled in the art to which the embodiments belong. Therefore, thecontents related to the combination and modification should be construedto be included in the scope of the present disclosure.

The foregoing embodiments and advantages are merely exemplary and arenot to be construed as limiting the present disclosure. The presentteaching can be readily applied to other types of apparatuses. Thedescription of the foregoing embodiments is intended to be illustrative,and not to limit the scope of the claims. Many alternatives,modifications, and variations will be apparent to those skilled in theart.

What is claimed is:
 1. A light emitting device comprising: a conductivesupport member; a first conductive layer disposed on the conductivesupport member; a second conductive layer disposed on the firstconductive layer; a light emitting structure comprising a firstsemiconductor layer disposed on the second conductive layer, a secondsemiconductor layer disposed between the first semiconductor layer andthe second conductive layer, and an active layer disposed between thefirst semiconductor layer and the second semiconductor layer; and aninsulation layer disposed between the first conductive layer and thesecond conductive layer, wherein the first conductive layer includes aconductive via penetrating through the second conductive layer, thesecond semiconductor layer and the active layer and being disposed inthe first semiconductor layer, wherein the insulation layer is disposedon a lateral surface of the conductive via, wherein a height of theconductive via is greater than a height of the insulation layer disposedon the lateral surface of the conductive via, and wherein the lateralsurface of the conductive via is inclined.
 2. The light emitting deviceof claim 1, wherein an angle between the lateral surface of theconductive via and a top surface of the first conductive layer is anobtuse angle.
 3. The light emitting device of claim 1, wherein theinsulation layer comprises a first insulation layer disposed on thelateral surface of the conductive via and a second insulation layerdisposed between the first conductive layer and the second conductivelayer, and wherein an angle between the first insulation layer and thesecond insulation layer is an obtuse angle.
 4. The light emitting deviceof claim 1, wherein the second conductive layer comprises one areaexposed outward, and further comprising an electrode pad disposed on theexposed area.
 5. The light emitting device of claim 1, comprising apassivation layer disposed on the lateral surfaces of the light emittingstructure.
 6. The light emitting device of claim 1, wherein the topsurface of the conductive via has a roughness surface.
 7. The lightemitting device of claim 1, wherein the top surface of the firstsemiconductor layer has a roughness surface.
 8. The light emittingdevice of claim 1, wherein the area ratio of the bottom surface of theconductive via to the top surface of the conductive via is from 1 to2.5.
 9. The light emitting device of claim 1, wherein the thickness ofthe insulation layer disposed on the lateral surface of the conductivevia is equal to or larger than 200 nm and equal to or less than 1000 nm.10. The light emitting device of claim 1, wherein the second conductivelayer comprises at least one of a reflective layer and an ohmic layer.11. A light emitting device comprising: a conductive support member; afirst conductive layer disposed on the conductive support member; asecond conductive layer disposed on the first conductive layer; a lightemitting structure comprising a first semiconductor layer disposed onthe second conductive layer, a second semiconductor layer disposedbetween the first semiconductor layer and the second conductive layer,and an active layer disposed between the first semiconductor layer andthe second semiconductor layer; and an insulation layer disposed betweenthe first conductive layer and the second conductive layer, wherein thefirst conductive layer includes a conductive via penetrating through thesecond conductive layer, the second semiconductor layer and the activelayer and being disposed in the first semiconductor layer, wherein theinsulation layer is disposed on a lateral surface of the conductive via,wherein a height of the conductive via is greater than a height of theinsulation layer disposed on the lateral surface of the conductive via,and wherein a width of a lower portion of the conductive via is greaterthan a width of a upper portion of the conductive via.
 12. The lightemitting device of claim 11, wherein a width of the conductive viabecomes narrower toward the upper portion from the lower portion. 13.The light emitting device of claim 11, comprising a passivation layerdisposed on the lateral surfaces of the light emitting structure. 14.The light emitting device of claim 11, wherein the top surface of theconductive via has a roughness surface.
 15. The light emitting device ofclaim 11, wherein the top surface of the first semiconductor layer has aroughness surface.
 16. The light emitting device of claim 11, whereinthe area ratio of the bottom surface of the conductive via to the topsurface of the conductive via is from 1 to 2.5.
 17. The light emittingdevice of claim 11, wherein the thickness of the insulation layerdisposed on the lateral surface of the conductive via is equal to orlarger than 200 nm and equal to or less than 1000 nm.
 18. A lightemitting device comprising: a conductive support member; a firstconductive layer disposed on the conductive support member; a secondconductive layer disposed on the first conductive layer; a lightemitting structure comprising a first semiconductor layer disposed onthe second conductive layer, a second semiconductor layer disposedbetween the first semiconductor layer and the second conductive layer,and an active layer disposed between the first semiconductor layer andthe second semiconductor layer; and an insulation layer disposed betweenthe first conductive layer and the second conductive layer, wherein thefirst conductive layer includes a conductive via penetrating through thesecond conductive layer, the second semiconductor layer and the activelayer and being disposed in the first semiconductor layer, wherein theinsulation layer is disposed on a lateral surface of the conductive via,wherein a height of the conductive via is greater than a height of theinsulation layer disposed on the lateral surface of the conductive via,and wherein an area of a top surface of the second semiconductor layeris greater than an area of a bottom surface of the second semiconductorlayer.
 19. The light emitting device of claim 18, wherein an area of atop surface of the active layer is greater than an area of a bottomsurface of the active layer, and wherein the area of the top surface ofthe active layer is greater than the area of the top surface of thesecond semiconductor layer.
 20. The light emitting device of claim 19,wherein an area of a top surface of the second conductive layer isgreater than an area of a bottom surface of the second conductive layer,and wherein the area of the top surface of the second semiconductorlayer is greater than the area of the top surface of the secondconductive layer.